The present invention relates to a fuel feed system for feeding fuel for fuel injection valves of an internal combustion engine.
Regarding such a fuel feed system, mechanisms utilizing a single diaphragm to reduce fuel pressure pulsation are disclosed in JP-A-2001-55961, JP-A-2001-59466, JP-A-2000-297725, JP-A-2000-266183, JP-A-2000-265926, JP-A-2000-249019, JP-A-2000-193186, and Japanese patent No. 3180948.
Moreover, methods utilizing a metal bellows as the mechanism to reduce fuel pressure pulsation are disclosed in JP-A-2001-82290 and JP-A-2001-59466.
Furthermore, methods utilizing a rubber diaphragm as the mechanism to reduce fuel pressure pulsation are disclosed in JP-A-2001-65427 and JP-A-2000-265925.
However, the inventors of the present invention have found that the above described prior embodiments have a following disadvantage. That is, when a single diaphragm is used as a mechanism to reduce fuel pressure pulsation, it becomes necessary to make the diaphragm large-sized to sufficiently suppress the pulsation because it has a low capacity of reducing fuel pressure pulsation.